Electron Sources

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Electron Sources 2017-02-28T17:04:44+00:00

STAIB Instruments offers state-of-the-art, reliable low-, medium-, and high- energy sources (up to 100 keV) with beam currents and spot sizes to match most applications.

Since 1987, STAIB Instruments has designed and manufactured electron sources with outstanding quality and dependability to ensure many years of use.  Numerous successful installations, coupled with excellent customer relations, form the basis for on-going developments of the product line to stay current with scientific research needs.

A large selection of electron sources are available.  All include optical designs, optimized by computer simulation, that require no on-site adjustment.  Filaments are affordable and can be exchanged on-site by the user.  Electronics are kept up-to-date with the best available parts, while support of older systems can also be obtained.  At STAIB, customer support is a high priority, as users will confirm.

STAIB systems provide excellent return on investment.  Reliability, ease of use, and low maintenance requirements ensure long usable life at low cost.  All electronic parts have self diagnosis for fast and affordable service.

staib-instruments-microfocus-EM802-pic01

These universal use electron sources provide a wide range of beam currents and spot sizes, including but not limited to those shown below. Typical applications include AUGER (AES), Energy Loss Spectroscopy (ELS), X-ray analyses (XPS) and cathodoluminescence studies.

High current versions (-HC) are available.

Max. Energy Max. Beam Current  Model Description
3 keV 20 µA » ES-380
3 keV 300 µA » ES-380-HC
5 keV 20 µA » ES-550
5 keV 300 µA » ES-550-HC
10 keV 40 µA » ES-1050
10 keV 200 µA » ES-1050-HC
These electron sources generate a very small spot in the µm and nm range. They are primarily used for imaging (SEM) and Scanning AUGER Microscopy (SAM).

Min. Spot Size Max. Energy  Model Description
<85 nm 15 keV » EF-15005
150 nm 12 keV » EF-1201
250 nm 12 keV » EF-1202
400 nm 10 keV » EF-1005
2 µm 8 keV » EM-802
3 µm 5 keV » EM-503
6 µm 5 keV » EM-506

 

Fine focus electron sources are available as part of the STAIB UHV-SEM package, and may be coupled with:

In addition for Nanofocus sources:

Flood electron sources are designed to provide a wide, homogeneous electron beam with adjustable spot size, intensity, and energy. Applications include space simulation, materials testing, charge neutralization, and detector testing.

Max. Energy  Model Description
100 eV » F01CC
5 keV » EMF-5
10 keV » EMF-10
20 keV » EHF-20
30 keV » EHF-30
40 keV » EHF-40
50 keV » EHF-50
60 keV » EHF-60
80 keV » EHF-80
100 keV » EHF-100
These universal use electron sources provide a wide range of beam currents and spot sizes, including but not limited to those shown below. Typical applications include Auger (AES), Energy Loss Spectroscopy (ELS), X-ray analyses (XPS) and cathodoluminescence studies.

Max. Energy Max. Beam Current Power  Model Description
3 keV 300 µA » ES-380-HC
5 keV 300 µA » ES-550-HC
10 keV 200 µA » ES-1050-HC
20 keV 0.5 mA / 1.0 mA  10 W / 20 W » EH-20-10 / EH-20-20
30 keV 1.0 mA / 3.3 mA  30 W / 100 W » EH-30-30 / EH-30-100
40 keV 0.5 mA / 1.0 mA  20 W / 40 W » EH-40-20 / EH-40-40
50 keV 0.5 mA / 1.0 mA  25 W / 50 W » EH-50-25 / EH-50-50
60 keV 0.5 mA / 1.0 mA  30 W / 60 W » EH-60-30 / EH-60-60
80 keV 0.5 mA / 1.0 mA  40 W / 80 W » EH-80-40 / EH-80-80
100 keV 0.5 mA / 1.0 mA  50 W / 100 W » EH-100-50 / EH-100-100
These electron sources deliver a high power density beam into a small spot, for applications including evaporation, X-ray generation, thermal shocks, annealing, and detector testing.

Max. Energy Spot Size
 Model Description
20 keV  <150 µm » EH-20
30 keV  <150 µm » EH-30
40 keV  <150 µm » EH-40
50 keV  <150 µm » EH-50
60 keV  <150 µm » EH-60
80 keV  <150 µm » EH-80
100 keV  <150 µm » EH-100
60 keV  50 µm » GDS 60 (for GED applications)
These electron sources provide a high beam current at low beam energies as needed for dissociation, ionization, excitation, and charge neutralization. A special model with very low energy dispersion is available for inverse photoemission.

Max. Energy Max. Beam Current Special features
 Model Description
100 eV 100 µA » NEK-150
100 eV 100 µA scannable » NEK-150-SC
100 eV 20 µA for charge compensation » F01CC
The robust design of STAIB RHEED systems is unique and operates reliably in real time growth and processing environments to provide invaluable information about the surface of a material. STAIB sources are known world-wide for high quality, years of dependable operation, ease of use, and unbeatable service. These systems are the first choice for MBE, PLD, sputtering deposition, CVD and more in chambers from large production sites to small customized chambers.

RHEED Systems are available for:

  • Wide range of maximum energies to best suit the application: 12kV to 60 kV
  • Wide range of adjustable beam current
  • Fine, bright focus spot
  • High precision and stability beam steering
  • Single and Double Differential pumping for additional growth environments
  • Full computer control
  • Low noise beam current option for combined RHEED-AES applications
  • Small flange mounting to fit all vacuum chambers
  • Fast beam blanking with external control
  • Customized shielding and designs for challenging environments

 

Max. Energy  Model Description
12 keV » RHEED-12
15 keV » RHEED-15
20 keV » RHEED-20
30 keV » RHEED-30
35 keV » RHEED-35
40 keV » RHEED-40
50 keV » RHEED-50
60 keV » RHEED-60
The unique design of STAIB’s electron sources has several advantages over the classic triode gun configuration.

Beam blanking is one such advantage. The beam can be switched on and off electrically, using a manual switch, controlling electron extraction from the filament. This method avoids the generation of stray electrons.

Additionally a full beam blanking option is available. Here the electron beam can be turned on and off using a TTL type input through a BNC connector.

The full beam blanking option can be used to keep the electron load on the sample very low. Electron bombardment of sensitive surfaces can be kept to a minimum. The blanking signal can also be triggered synchronously with external signals to improve the use of the electron source in the presence of stray magnetic fields by compensating their effect. The external trigger can also be utilized to synchronize with rotating samples, which is important for in situ monitoring in some deposition techniques.

Electron sources from STAIB produce an electron beam that can be pulsed to produce sharp power pulses up to the microsecond range. Applications include sample annealing, heat treatment, evaporation, heat shocks, and luminescense studies.

Beam pulsing is available on all focused electron sources offered by STAIB Instruments. Several standard pulsing options are available to cover a wide range of frequencies. Customization is also available to meet the needs of specific experiments, such as additional ranges of pulse widths.

Fast pulsing systems
Pulsing to 100 Hz can be provided as an option to the electron source power supply. For pulsing beyond this frequency, in addition to the electron source and power supply, a pulsing unit plus a special high voltage cable, that provides an input from the pulse unit (a pulse control signal), are needed. The pulsing unit has an internal clock or allows an external TTL pulse signal to give it a reference signal. Several standard pulsing units are available to cover a large range of frequencies. Other ranges of pulse widths are available on request.

Pulsing unit FP-1 FP-10 FP-100
Minimum pulse length 3 μs 10 μs 100 μs
Maximum pulse length 50 μs 200 μs 20 ms

Please contact our office for specific details.

In many challanging environments, the vacuum conditions are not good enough to operate an electron gun.

Electron sources from STAIB Instruments are available with a differential pumping option for pressures greater than 10-5 mbar. By utilizing a turbo pump (>40 l/s) attached to a special flange on the electron gun, the system continues to work well up to a few 10-3 mbar. Efficient pumping of the filament section of the source offers unbeatable versatility. For higher pressures, the double differential pumping option (e.g. TorrRHEED™) is available, which still allows the complete electronic control of the beam.

STAIB Instruments has designed a patented system of beam steering that electronically controls the beam position and deflection angle.

With the patented STAIB Advanced beam steering™, the beam angle can be changed with a unique double deflection system. The beam can easily be manipulated on the sample without changing a mechanical alignment. This gives the operator the desired degrees of freedom for easy and simple alignment of the electron beam setup. Even double beam rocking can easily be performed.

The Advanced beam steering™ is also used in the parallel beam shift option, which combines beam rocking (in X) and the parallel shifting of the beam (in Y). The electron beam can thus be used to analyze different positions on the sample at the same angle (incidence and azimuth).
The computer control option for STAIB electron guns consists of two parts.

1: Power supply computer control plug
The electron source power supply is equipped with an optional computer connection plug for use with analog control signals. The electron source system can either be operated by using the manual control dials, or by using the optional computer control. The control voltages can either be provided by 3rd party software through a suitable DAC interface, or by the STAIB computer control module.

2: STAIB computer control module
The STAIB computer control option includes the cables and microprocessor interface to connect to the power supply computer control plug. The STAIB software sends the input signals to the power supply to control the system functions. Full parameter sets can be stored, modified, and reused. The advanced version of the STAIB computer control module can retrieve and copy the adjusted values from the manual control dials, providing the user with previously unavailable ease of use.

The option runs under the WindowsTM XP, WindowsTM 7, WindowsTM 10 operating systems, using a USB connection.

STAIB Instruments electron sources can be equipped with magnetic shielding. The shielding may be necessary because a magnetic field influences the electron beam. A static or DC magnetic field will shift the beam and an alternating field will wobble the beam. This can cause fluctuations in beam position, size and current.

The magnetic shielding is made of a highly ferromagnetic material. For this reason, it can be used to shield low frequency magnetic fields from the surrounding environment.

STAIB Instruments offers Scanning Electron Microscopy (SEM) products designed around our electron sources.

For beam diameters below ca. 10 microns, bright and detailed images of the sample are obtained in SEM mode. A number of specific electron guns covering a wide range of beam diameters and energies are available.

The elements of the system are:

  • Electron gun and power supply
    Any of our microfocus sources may be used. Other STAIB electron sources may be used if higher lateral resolution is not needed.
  • Scanning amplifier
  • Current amplifier
  • Secondary electron detector
  • Data acquisition system
Electron sources from STAIB Instruments are uniquely designed to allow precise electronic control of the beam position and current. Sophisticated electron beam deflection optics accurately control the beam position onto the
sample.

Features achieved by this precise control are:

  • Full compensation of the earth’s magnetic field for all beam energies.
  • Energy compensated deflection of the beam. During analyses, the beam energy can be
    changed without readjusting the focus or beam position.
  • The deflection optics allow the capability of electronic beam rocking. The electron path is shifted
    off axis in the gun and refocused onto the sample, maintaining the spot position. In this way,
    the incidence angle can be controlled electronically without either modifications of the geometry of
    the gun or motion of the sample. The electron gun can be mounted on the vacuum chamber
    without using a bellows for mechanical adjustment.

The electronic beam control option is very helpful in even more critical cases where the sample position cannot be adjusted easily during the growth. In this case, beam rocking allows a precise variation of the incidence angle.

The Beam Current Controller (BCC) is a microcontroller based unit used to regulate the electron beam current of the electron gun, as used in RHEED or AUGER techniques.

Regulation of the electron beam current to a fixed, precise, user-adjusted value is important when the electron gun is working in a higher pressure range and when using reactive gases in the vacuum chamber. Once adjusted, the BCC will regulate the beam current to the assigned value, even after gun parameters like beam energy or focus are modified. Operating values can be saved and will be kept after restarting the BCC module, ensuring identical experimental conditions.

Spare filament delivered in a sealed container for customer installation. Directions for filament exchange are provided.

Spare filament already mounted, and pre-aligned in spare firing unit.

The kit contains one spare filament and tools for standard maintenance.

The major functions of the power supply can be easily tested using the diagnostic box connected to the diagnostic plug on the rear of the power supply.